Update node-api parts #688
Description
We should check the following files are still up to date:
- https://github.com/scs/substrate-api-client/tree/master/node-api/src/events
- https://github.com/scs/substrate-api-client/tree/master/node-api/src/metadata
- https://github.com/scs/substrate-api-client/tree/master/node-api/src/error
Follow up issue of #687